


目が合ったら

by ttsutsuji



Category: Original Work
Genre: Brothers, F/M, High School, Romance, Slow Burn, Twins, i have been thinking about this since forever, i'm a weeb so they're japanese lol, lowkey physics, no beta we die like men, psychology but it's just a girl being a hardcore psychology enthusiast, this will most likely have only one fan who happens to be my friend
Language: English
Status: In-Progress
Published: 2019-09-24
Updated: 2020-06-25
Packaged: 2020-10-27 14:28:43
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 6,665
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20761871
Author URL: https://archiveofourown.org/users/ttsutsuji/pseuds/ttsutsuji
Summary: Apparently physics can't solve every problem.





	1. Attitude and Prejudice

**Notes for the Chapter:**

> damn i'm finally writing this after a year. i'm weeb shit so naturally names are japanese, if you're curious about their names' kanjis it's 空夕続 for sora, 夢躑躅 for yume and 夜洋紅 for yoru

_Tick, tock, tick, tock..._

Hour and minute hand of Sora's watch moved together in harmony, making sounds no one else but Sora paid attention to. In the classroom full of students whispering things to each other, the ticking sound was the only thing Sora could focus on. It was almost time that this class ended- yeah. Just a minute, and one more hellish class would end, giving place to ten minutes of peace. Though, never in his life would things go that smoothly- as if sensing his little bit of peace, the teacher announced.

"I would like you to make a group project. Everyone, choose a partner for yourselves. I want you to do a commentary on a book of English literature. It seems as if we're running out of time. I'll give details next class, class dismissed."

_Tick, tock._

Yes, just as the hands of the watch hit the exact numbers, the bell rang. The bell that was supposed to give a sense of relief to Sora was no longer useful, his peace was already tied with red ropes and thrown off a building. _"A group project," _Sora thought, _"how useless. Why is it even a group project, again? Such a thing should be child's play. Yeah, it'd be better to be partners with whoever and spare them the effort... Yeah, that'd be nice." _In such a short amount of time, the problem and it's solution appeared. But Sora still felt troubled.

_Hmm, hmm, hmm..._

The word "partner" rang in Yume's ears, but rather than actually focusing on the meaning of the word, her mind was occupied with a melody, making her hum instead of focusing on anything else. _Partner, partner, partner..._ _"Hmm, yes, a partner..."_ after repeating the words in her mind like a broken tape, she ran the tape in her mind back, repeating the memory of the teacher's words. _"Commentary on a book... Piece of cake." _her clouded mind still wasn't free of the melody stuck to it, she dazedly looked at the classroom, then turned to the window, adoring the scenery before her once again. Of course, if she were to get a partner, that'd be Yoru, no brainer to everyone. _"But it'd be nice to make small changes every now and then. Or the world would be so boring..."_ she hummed happily to herself, slowly getting rid of the melody surrounding her thoughts. She directed her attention to the classroom, her gaze instanly being snatched by a certain someone.

_Hmm._

Yes, just as the melody ended and left Yume's mind, Sora caught her gaze. The boy stood on his seat, reading a book quietly. Perfect match for a little change. Yume didn't have to force her body to stand up and leave the comfort of her own seat as Sora was sitting right next to her- yes, how strange. Despite sitting next to each other since the start of their second year, they didn't know anything about each other, did they? That is an irrelevant question.

"Yuuzoku-san." With her iconic respect and calmness, Yume looked at Sora as she said the words, having her usual faint smile painting her face.

Sora looked at Yume, first questioning himself if he heard Yume right, then questioning himself about if he knew the last name of the girl sitting next to her or not. After a little inner debate with himself, he responded. "...Tsutsuji-san."

"Would you like to be my partner for the project?"

This question brought so much questions with it, and only one answer. First of all, yes, Sora in fact did know Yume's last name. But, wasn't this girl supposed to chose her all time best friend for a project? Is this some kind of prank- no, it most likely isn't. Just look at the maturity of this girl. She was great at English, wasn't she? Maybe he'd have the opportunity to spare himself some effort if he accepted her offer, but why him? Drowning in these thoughts, in an effort to deem them all useless, Sora responded with a firm "Sure.", the interrogation could be saved for later.

"I am glad to hear that, Yuuzoku-san. If you're free, let's meet up in the library after school?"

Library after school? Maybe she was planning on murdering Sora? No, that couldn't be the case, despite being a harsh and rude person, Sora didn't remember wronging Yume or someone dear to her, but every murder wasn't committed out of resentment. Though she did look like she could kill someone, just look at that black coat, who even wears a coat on a school uniform- no, no, even if she did want to kill him, library would be a stupid choice of her. Hey, even if he was chased by a murderer, at least he wouldn't have to go home.

"Yeah, that'd be good."

_Tick, tock, tick, tock..._

"I am wondering why you'd choose me instead of that... friend of yours." Sora tried his best not to come off as rude, much to his benefit, Yume wasn't about to take any offenses soon.

"I like small changes."

_"Oh,"_ Sora let out a breath he didn't know he was holding, _"so this is seriously all there is to it?" _he could go with that.

_Tick, tock._

Last period started.


	2. An Accelerated Collision

**Summary for the Chapter:**

> chillin' at the library

_Ding, dong, ding, dong._

The bell rang once, twice, thrice, for the last time, this time signalling the departure of the students. However, two of these students weren't about to depart anywhere soon.

The ringing of the bell wiped away the impatient expression on Yume's face, now with her usual calm and mature look, she turned to Sora, who turned his head back at Yume as if sensing her gaze. The pair looked at each other for a moment as if waiting for the other to say something, in the silence of the two, Yume was sure that Sora was getting uneasy. Much to her expectations, Sora turned his head away after a relatively short time of eye contact, flustered.

"Shall we go, Yuuzoku-san?" With the delight of predicting another person's future behaviours right, Yume chimed.

"We shall."

The walk to library wasn't short, but it was silent. Sora looked at Yume, wondering why and how she was looking so comfortable around a complete- maybe not complete- stranger. Maybe this serenity of her was the thing unnerving him the most- why would calmness disturb him? Maybe it was because he was never used to seeing it in another person, but Sora was completely unaware of that.

Every now and then Sora would stop looking at Yume, feeling that she could sense his gaze on her... at any given moment.

"What book do you suggest we use for the project, Yuuzoku-san?" Yume's sudden words made Sora snap out of his uncomfortable thoughts, only to have them give place to unease caused by her easy going nature.

"Uh... Do you have suggestions?"

"Have you ever read works of Mark Twain... or Agatha Christie? Actually, I'm good with any famous authors, Orwell, Dickens or-"

"Wait, stop. Before you go any further, Tsutsuji-san, I have not read any works of these authors you counted. Matter of fact, I do not think I have read any famous works of English literature, ever." Sora said in an attempt to stop Yume from rambling about all these authors he have definitely heard of, but never paid attention to.

Yume, on the other hand, for the first time showed Sora an emotion other than modesty, which happened to be confusion. The girl stood in front of him with half-wide eyes, apparently not ready for that answer. "None, ever, you say," she began questioning, "not even Shakespeare?"

"No."

Yume kept the confused expression for a while before completely wiping it away from her face with the blink of an eye, too fast for a normal expression to change, fast enough to make Sora think she was certainly putting up an act and maybe he was certainly going to be murdered in the library.

"Well, it doesn't really matter~ Shakespeare is boring anyways. Just a bunch of dialogues and ambiguous actions..." Yume let herself slip into sarcasm, though her voice never gave the smallest hint of her being cynical. Even though it was impossible to tell if she was being serious or not based on her voice, Sora interrupted.

"You don't think like that."

"Huh?"

_"...Huh..?" _Sora slowed down for a little bit, repeating Yume's question in his head, _"Certainly, huh, how do I know such a thing..?" _

"You just don't look like the person to think so... lowly of a famous author." By this point Sora didn't know if these words he let out were the truth or a sheepish lie to get out of this odd situation.

Yume raised her eyebrows at Sora's answer and smiled, this time not a mature and modest smile but rather a childish one. "Why, you're certainly right, Yuuzoku-san. While not enjoying his works as much as I enjoyed other famous authors', I do respect his literature's quality. I wonder how you understood that I was being cynical..?" Towards the end of her sentence, Yume turned her head to Sora, as if looking for an answer to read off of his expression. 

To Sora's relief who didn't want to give out an answer as to why he could figure something like that about Yume out so quickly, they were at the library's entrance, where silence was the law, though it was relatively empty when the school had just ended. Maybe Yume knew that library was going to be this secluded at this time of day... Maybe she set that up? Oh, Sora was definitely, most definitely getting murdered. What a way to go- or not.

"Even though I see you reading all the time, Yuuzoku-san, it comes off as strange to me that you never read a work of English literature before." Once again Yume's words snapped Sora out of his daze, yeah, maybe it was just better to keep talking to her.

_"She has been paying close attention to that... or I am doing seriously nothing but reading? Yeah, this is not something only a murderer would notice." _

"They're mostly about physics." Sora said in a matter-of-fact tone, not wanting to be ridiculed by Yume.

"I realized that much. You seem to have a genuine interest in physics, Yuuzoku-san. How intriguing."

"Interesting... how you say intriguing, Tsutsuji-san." Coldly turning his head away from Yume, Sora seemed to be secretive about his interest. Though his reaction could be considered rude by others, Yume was delighted to see such a reaction coming from Sora.

"Would you not say so, Yuuzoku-san? Instead seeing everyone become tasteless adults played like puppets by the ones around them, it's nice to see someone be interested in something other than school subjects." Guiding Sora to a bookshelf, Yume said happily.

"...Physics is a school subject? You know, as in sci-"

"No, Yuuzoku-san. I meant it as an interest in studying for exams and such only..." Yume, a little bit baffled by how dense Sora is, chuckled light heartedly.

"...Is that so."

Yume stopped in front of a certain shelf, taking a book and handing it to Sora. "If you have no experience on English literature, you can read this. It's short and you really won't have to give a second thought to it or look for a top-secret, cleverly hidden meaning."

"...The Strange Case of Dr. Jekyll and Mr. Hyde. I heard this before." Sora took the book and started examining it, concluding that this book wouldn't take much away from his day, judging by the shortness of it.

"I might be biased. This book is my favourite book, if I have to be honest." Yume put her hands behind her back and smiled as Sora looked up at her with a little hint of curiousity in his eyes, of course, only Yume could decipher such a slight emotion shown in his eyes.

"...Tell me why?"

Once again, Sora made Yume's smile turn into one of childishness instead of modesty, her trying to surpress her lips curving from so much.

"You see, Yuuzoku-san. Though such a message isn't this book's intention, I love to think of it as a story that shows that humans cannot contain malice in them for too long- else it'll ultimately make them lose their minds. Or kind of like to think the characters as... not separate people but archetypes of one people, y'know?"

"...Archetype?"

"Archetype as in psychology. Do not get me wrong, Yuuzoku-san, I am not a fan of psychoanalysis, but Jungian archetypes aren't half bad."

"...Huh. You seem interested in that, Tsutsuji-san." Sora said, _"Though I have no idea what psychoanalysis is..."_ thinking to himself.

"Yeah. Psychology might be the only thing I'd accept being a hooligan for."

"You say I'm intriguing, but isn't the one who's intriguing you, Tsutsuji-san?"

"Intriguing... Am I? You can find a lot of people who say they're interested in psychology~" Yume cooed happily, "Though I am not interested in fools who only say that they're interested and do nothing to pursue an interest or get any information about the so called interest... Dunces who claim to have an interest in psychology have became temporary nuisances in my daily life." This time Yume's voice was definitely getting cynical and condescending, that was obvious to everyone, not only Sora. Different emotions didn't change her expression all over, but only the smile she wore, this time her smile becoming seemingly... cruel.

"So we have some things in common."

Yume turned to Sora with interest in her voice, "Is it about both of us having unusual interests," she asked, "or both of us not being interested in fools?"

"I'd say both, Tsutsuji-san." Turning his back to Yume as if he was to look for a book at another shelf, Sora so slightly smiled to himself, worried that someone catching a smallest glimpse of his happiness could cause a pandemonium- again.

"...Well, I guess our job here is done. Shall we head to our homes?" Yume asked much to Sora's chagrin, who only wanted to stay at the library maybe a little bit longer, before going back to his hellish house- but he already avoided going there with... people tailing him, didn't he? Maybe going home -alone- after a weird interaction like this wouldn't be so bad. Just maybe.

"Yeah. Then, I'll probably be done with this book by tomorrow, Tsutsuji-san." Sora said and headed to the librarian to borrow the book. Yume, not heading to her own home to soon, made some quick steps to Sora's side.

Calling out with a little shake in her voice, "Then, I am looking forward to seeing what kind of person you are, Yuuzoku-san." she exclaimed.

Sora, apparently taken aback by Yume's weird declaration, asked, "Is this supposed to be an invitation to become friends, Tsutsuji-san?" though what he actually thought was far away from that, _"Is this a threat..?"_

Realizing that her intentions had been understood loud and clear, once again before showing anyone any other, Yume wore her elusive smile, "Of course it is." she chimed.

"Then, no need to call me by my family name... I hate it anyway."

"Sora-san is it?"

"Just Sora is fine."

"Is that so? Then, right back at you. Just Yume will do."

"...This has been... Quite weird of a meeting. Like a collision, even."

"Has it been? No normal meetings for no-normal people! Meeting someone resembling me was such fun, Sora." Yume grinned cheekily, putting a finger on her lips before turning back and making her way towards the exit.

_"Not a tasteless adult being played like a puppet... Is this what you thought of me?"_ Sora looked at the girl's disappearing figure, realizing his still existing pulse, _"Ah, I am not murdered."_


	3. Sensorimotor Stage

**Summary for the Chapter:**

> chillin while walkin. if you don't get the talk at the end check chapter notes

"Tsutsuji-san, I finished the book you gave me." Sora, sitting next to Yume in the almost empty classroom, said as he handed Yume the book.

Taking the book from Sora, Yume didn't wait for him to actually keep his word and be done with it in a day. However, her mind wasn't occupied with the thoughts of that, no, she was thinking of something completely unrelated to Sora's point.

_"Didn't we agree to go by first names yesterday... or was it a dream?"_

"Is that so," Yume said with her signature smile, her eyes closed, "how did you find it, Yuuzoku-san?"

Being called by his family name, with a slightly bothered voice Sora replied "Well, I liked it. What are this kind of books called... Gothic..?"

"Gothic... Yeah, that's the word."

"More importantly, a question."

"Hmm?" Sensing the troubled tone of Sora's voice, Yume, trying to sound curious, was already making assumptions about the question that he was going to let out.

"Didn't you agree on not calling me by my family name yesterday..?"

_"Bingo! Dead on! A hundred points!"_ were Yume's first thoughts. Taking pride in her correct predictions, she answered with a calm -or rather smug- voice, "You say that, Sora-san, but you just called out to me with a 'Tsutsuji-san', didn't you?"

Sora was surprised by Yume's love for reciprocity, though he'd eventually come to like it- after a good amount of time, that is.

"...Please give me time," the flustered Sora replied, "I am not used to being friendly with people." he shyed away a little towards the end of his sentence, looking away, which Yume didn't overlook.

"Ahaha, it's alright, Sora-san," Yume light-heartedly chuckled, "if that's the case, I'll try to refrain from calling you by your last name every time you do it subconsciously." though she said that, instead of Sora's unfamiliarity with intimacy, it was his hatred for his family name that made Yume want to stop using it- though Yume was probably the only one to realize such resentment Sora never expressed.

"Then, Yume-san," using the right addressing this time, "should we start working on the project today?" with the intent of getting done with the project as soon as possible, Sora asked Yume.

"This early?" Yume was taken aback by Sora's desire to get rid of the trouble of having to do a project, though she guessed that he would want to finish it without delaying. "Well, it's not a problem for me. Shall we go to the library after school again?"

"Yeah, I don't see why not." was Sora's reply, ignoring Yume's confusion altogether.

The school day went on without the duo uttering a word to each other again- everything was the same as the time they didn't know each other. Yume would call out to Yoru who sat right in front of her, Yoru would stop drawing whatever she wanted to portray at that moment and bend her head backwards- or the exact opposite, responding to Yoru's calls Yume would bend a little forward, stopping looking at the scenery outside, the two whispering in the class. Sora would act as if he was focusing on the class, all of his material present, but his mind totally occupied with different things- or at classes he felt better, a physics book in front of him, just ready to be hidden in case of a teacher approaching. The lively class was a noisy as usual, which would make Yume think _"Everyone seems to have fun." _and in Sora's case, _"Can't they shut up for a day?"_. The passing classes were not different than any other day's ones, with the blink of an eye, Yume would bid adieu to Yoru, Sora would pack his stuff, once again thinking about how the day he had left would be spent at his house.

His resentful thoughts were cut off by a gentle voice, "Shall we go, Sora-san?" Yume calling out to him, making him snap out of his troubledness, which was evident on his gloomy expression.

"We shall."

The duo once again began walking to the library together. This time, though, Sora's head was empty- not filled with thoughts of whether he was going to be killed or not, though there's no way of telling if he would truly care if Yume being a killer and him being the victim was the case here.

Letting out to her thoughts, or as if trying to test Sora, Yume asked "What sub branch of physics do you like, Sora-san?" with the usual smile of hers, though this time Sora focused on the question rather than her eerie smile.

"Let's see... I'd say astrophysics and optics, Yume-san, but I am no less than well informed about classical and modern physics. Despite being focused on astrophysics more than anything else, I am naturally interested in physics as a whole, I didn't really neglect any focal points of it, nor did I ever ignore a sub branch extravagantly." replied Sora, with a slight smirk appearing on his features.

_"Woah,"_ thought Yume, _"you seem happy to hear such a question, Sora-san."_

"What about you, Yume-san?" Sora continued his speech, "You mentioned liking psychology yesterday. What might be your favourite sub branch of that, I wonder?" he asked as if not waiting a proper answer.

_"Oh," _the girl gave off a knowing smile, _"so that's why you smirked like that, Sora-san!"_

With a smile akin to Sora's, Yume started, "That would most likely be clinical or cognitive psychology... Though I only choose that because it's the closest to my personal interest. To be honest, of course I can't overlook sub branches. Behavioural, clinical, cognitive and experimental psychology- all these four include parts of things I like, so I actually do not have a way of choosing one as my favourite. Since, unlike natural sciences, psychology is a fairly new science, it has yet to have a sub branch completely focused on the best part of human thoughts and subconscious-" she was getting a bit carried away, though Sora definitely wasn't expecting such a calculated-sounding answer, "it's such a shame that psychology still doesn't have a sub branch for dreams, but accept my favourite sub branch as dream psychology, I'll wait until the day it comes to life eventually."

A little shocked by Yume's answer -yes, he definitely wasn't waiting for Yume to actually give a reasonable one-, Sora looked bewildered. "Dream psychology, huh..." he said, though in his mind thinking _"That might come off as a little bit egoistical, Yume-san." _Giving voice to his suspicions that he thought could somehow sound offensive to Yume, "Would you think that's caused by your name, Yume-san?"

Yume, seemingly amused by Sora's reaction, happily chimed, "You're the one to talk, Sora-san. Aren't you focused on the sky the most?"

"Focused on the sky..? No- I'm focused on the things way beyond the sky." Sora stated with a dedicated tone, giving Yume a serious look.

Yume, firstly responding to Sora's seriousness with a confused yet curious expression, after running his words through her mind again, gave him a smile that wouldn't make him uneasy but surprise him with how genuine her happiness looked for once, cutely beamed, "You say that, Sora-san," she put her hands behind her back and leaned to Sora's side a little bit, "won't you see through me and understand that I want to see beyond dreams as well?"

Yume was definitely getting Sora's interest in her to grow, they found themselves in front of the library's door as they were yet oblivious to this.

**Notes for the Chapter:**

> sora thinks it's egoistical for yume to be interested in dreams because yume (夢) means dream in japanese. yume says "aren't you interested in the sky the most" because sora (空) means sky in japanese there you have it


	4. Absolute Zero

**Summary for the Chapter:**

> not chillin. i unleash my ultimate weeb. are you ready to witness me using the word onii-san

**Notes for the Chapter:**

> nadare's kanji is 雪崩 (meaning avalanche) and fubuki's is 吹雪 (meaning snowstorm)
> 
> i named them this way because they're both disasters.

_"Won't you see through me?"_

The words of Yume rang in Sora's mind. What did they mean? To see through Yume...

  
In the emptying classroom, Sora blankly looked at Yume who was once again today bidding her adieu to Yoru, yes, same as usual, her talk filled with "Be careful your way home"s and "Text me when you get home"s,one would think Yume was Yoru's mother instead of her friend- though Sora's mind had no space left to be occupied by such thoughts. 

  
"Would you care sticking with me in the classroom for a little while after classes end, Sora-san?" was what Yume told Sora at the beginning of the day, a weird request, but Sora didn't mind- it was long established that Yume had no intentions of killing Sora (or she was a very talented killer and wanted to build a relationship for an easier target) and she was, even though Sora wouldn't admit that to himself for a while, more interesting to Sora than anyone he ever laid eyes on. So, a simple "Sure." was his answer.

  
Yoru had now left the classroom, giving Yume and Sora their solitude at last. Yume turned to Sora, with a smile, "Thanks for waiting for me, I hope I'm not holding you from anything?" was how she started the talk.

  
"No, not at all." Sora stated, "You're actually doing me a favor by making me go home late for these past days." was what he wanted to continue with, though there was no way he'd actually say that.

  
"Nice." saying that, Yume started going through the stuff in her school bag. Searching for a little while, after having found the thing she had been searching for, she took a book out of her bag and handed it to Sora. "Since you said you weren't experienced with novels, I wanted to give this to you."

  
"...The Moon is A Harsh Mistress..? Not a bad choice for a name now, is it?" Sora grinned a little bit, taking the book from Yume's hand. He started to examine it, yeah, it wasn't too long for him, he had probably finished longer physics books overnight- a book that doesn't need that much braining would be a piece of cake. "So then, what is this book about?"

Yume gave off a troubled expression. "It's science fiction. The story revolves around a world where, with the advanced technology, people send off death row inmates- or just people they just can't stand to the Moon. The people at the Moon then become a 'civilization' and... Ah, things happen." Obviously not wanting to talk about the story of the book, Yume quickly shooed Sora's question away and continued, "Since you said you liked astrophysics, I could only come up with this as a novel that you'd enjoy. Ah, there's also a character called Mike. He reminds me of you."

Now intrigued, Sora thought, _"Maybe it will be fun reading this... Not as much as Michio Kaku- but I'll let this one pass." , _turning his head to Yume, he spoke, "Mike, huh? He likes physics too?"

"I wonder? I thought of you two personality wise."

"Do you think physics doesn't make up an important part of my personality? You've got high expectations, Yume-san."

The small talk between the two was lively. Maybe, if it didn't get disrupted, it would lead the duo to more enjoyable topics- though such a possibility was quickly eliminated when the door of the classroom was shut open, startling the two students inside, the other side of the door revealing two identical looking boys- though their appearance was almost the same, save for the little height difference and how one of them had his uniform in good trim while the other's was looking like one of a delinquent's, the contrast between their expressions was evident as one was looking like a lost puppy looking for it's owner with a smile, while the expression of the other one screamed bloody murder and impatience.

"Kouhais..?" Yume quietly muttered to herself.

"For the love of Jupiter, fuck no..." Yume heard Sora mutter under his breath with a fed-up expression.

"Oh, there you were, Onii-san!" The shorter and definitely the brighter of the two walked into the classroom with steps that resembled the ones of a child, while the other only stood at the door with a disgusted expression, sighing. "We were looking for you! Who is this lady? A friend of yours?"

Yume only looked at Sora whose expression screamed "Please get me out of this situation." to whoever could help him. Getting his message, Yume answered for Sora with her iconic smile, ready show her calm nature to someone new, "We're friends, yeah."

"Oooooh! My first time seeing a friend of Nii-san's!" the eyes of the boy who had now made his way to Yume sparkled even brighter, so bright that Yume thought it was possible to find a star or two hidden in those orbs. Taking her hands and pulling them towards himself and getting a dark glare from his elder brother, the boy cheered with a childish smile, "You're soooo pretty! What is your name?"

"Tsutsuji... Yume." Yume was definitely bewildered by how vivid and cheery Sora's little brother was- at least assuming that they're brothers by the way this one calls Sora.

"Uwooaahhhhh! Such a pretty name too! I'm Fubuki, and this gloomy one that's identical to me is Nadare! Well, you see, Yume-nee-san, we'll have to snatch Onii-san away from you for today, but tomorrow we'll DEFINITELY come here to get to know you better, right? Right?" the emphasis of the word "right" sounded like a plea to both of his fed-up brothers, though Yume was amused by how lively this kid was.

"Fubuki, don't you have manners?" Sora scolded his little brother, though Fubuki was too busy with examining Yume to actually care about that.

"How bright you are," with a heart warming smile this time, Yume pulled her hands out of Fubuki's grasp and gave a little pat to his head, which he responded with a happy hum, "alright. I'll set your brother free. Though be more aware of his wants when you come here again- Sora-san is making quite the scary face." she chuckled towards the end of her sentence, making Sora give her a troubled expression.

"Get it over with already..." Nadare, resting his back against the door spat out with his arms crossed, looking at his elder brother with resentment, which Sora gladly returned.

"Mmmhmmm! Let's go, Nii-san!" Without giving the slightest care about the glaring match between his brothers, Fubuki grabbed Sora's arm, forcefully dragging his brother out of the classroom. Before being completely pulled out by Fubuki, Sora shouted from across the classroom.

"Thanks for the book, Yume-san!"

With awe in his eyes, Fubuki exclaimed, "Waaah! You're already on first name basis!"

"You're the one to talk!"


	5. Entropy of Similar Beings

**Summary for the Chapter:**

> not so chillin. using "-chan" gives me literal cancer but it's just the kind of person fubuki is

"Such pretty hair! What was the last time you cut it?"

"It hasn't been long actually, though I do not get it cut of-"

"It's sooooo long! It's a bit messy though, I bet Yume-nee-san would look like Rapunzel if it was completely straightened!"

In the lively classroom at morning stood Fubuki, trying to get to know Yume on every single aspect, being as loud as possible while being completely oblivious to this fact. He had gotten the attentions of a lot of his seniors, though he was too occupied with his elder brother's new friend to realize that, or the glare of his twin whom he dragged here.

"Yeah, when they're combed they become so straight to the point of trailing on the floor, so-"

"Yume, who might this be?" Once again without being able to finish her sentence, Yume was interrupted by Yoru this time who had just woken up from her sleep (most likely because of Fubuki).

Fubuki directed his gaze towards Yoru, observing her for a second with a blank second, then yet again smiled brightly and extended his hand at Yoru, waiting for a handshake.

"Yuuzoku Fubuki, nice to meet you!"

Sleepily taking Fubuki's hand and shaking it, Yoru replied, "Yuuzoku? Oh, you're the brother of the top of the class?"

"Ah! I knew that Nii-san was always a good student but never knew that he was the top of his class!" Fubuki exclaimed in excitement, now turning his head towards Sora, "Nii-sannnn! Why wouldn't you tell us about this?" he questioned.

"Please just shut the fuck up," Sora sighed with his head in his heads, completely worn out just by listening to Fubuki's rambling. "For the love of Jupiter just leave."

"No, I do not think I will." was Fubuki's reply, determination shining in those bright eyes of his.

"Though I hate agreeing with Aneue-sama on anything," Nadare said, shooting a glare to Sora while doing so, "please, let's just go, Fubuki. Why are you interested in the friend of someone like HIM, anyhow?"

"I think you're being unfair to your brother." Yume directed at Nadare with her usual kind and modest nature, though she doubted that Nadare would be affected by her calmness.

"No, you're a moron." He spat out.

"You too, please shut the fuck up." Sora scolded the harsher of the two twins this time, not having the energy to glare, just sighing with a tired expression.

"Woah! How great, Yume-nee-san! It's my first time being scolded this kindly by Nii-san! Being around you really does the trick, eh?" Fubuki asked Yume, his smile never disappearing.

"Hmm," Yume ignored Fubuki's question, "tell me, are you interested in physics like your brother?"

"Nu-uh, not at all. I like chemistry though!"

"How nice. You must be better at understanding physics than me, though."

"Hmm~ Natural sciences are similar, so I do not have great problems with physics. Biology is a hassle, though~" Fubuki cooed, now calming down a little bit, maybe being effected by Yume's personality.

"No, it isn't, biology is child's play." Nadare interrupted.

"Biology, huh..." Yume mumbled while petting Fubuki's hair (which was completely unnerving to Sora and Nadare, and relaxing to Fubuki), "I might be knowledgeable about human biology... that's all I know, though."

Sending Yume an offensed look as if he was being challenged by her, Nadare questioned his senior with a harsh manner, "...Which part of the brain controls sleep?"

"Huh? Hypothalamus?"

"..."

"..?"

"I was waiting for a more precise answer. I'll take it for the time being though."

"You really don't have to test me." Yume told Nadare with an amused smile.

"No, I shall."

"Just get off your high horse!" Sora interrupted the small quarrel between Yume and Nadare, having enough of his brother's egoism.

"It's Aneue-sama who's on a high horse!" Nadare fought back, now directing his angry expression towards his elder brother.

Fubuki happily watched the bickering between the two of his brothers, as if he was used to such fights by now. Yoru looked at Fubuki with a worried expression, confused to see him have such a positive mood despite his brothers fighting, while Yume watched Sora with a gentle smile, taking out a notebook and starting to note some things on it.

"What are you writing, Yume-nee-san?" Fubuki asked, distracted from the fight.

"Hmmm... Nothing important." Yume ignored Fubuki's question, not taking her attention away from the notebook.

Yoru chimed in, "If it's her, ya bet she's takin' notes of the fightin' of those brothers of yours." with one eyes closed, she smiled while pointing her finger at Yume.

"Touché..." Yume mumbled, chuckling a little bit at her friend's remark.

"By the way, Fubuki."

"Hmmm?"

"Name's Yoru." Yoru smiled, still keeping one eye closed.

"Hmm~ Nice to meet you, Yoru-chan!"

_"Gettin' too formal too quick." _Yoru thought, though she wouldn't want to scold such a bubbly child.

The fast-paced short-lived morning talk of the five was enjoyable to at least the majority of them. Noting the new behaviours of her new friend, Yume beamed at the quarrel between Sora and Nadare, filled with meaningless insults that wouldn't reach anywhere- _"Brotherhood fights, no need for logic..." _she thought, writing down the scene happening before her. Soon, the bell would ring, making the twins leave, with the classroom getting quieter Yoru would fall into another slumber, Sora would calm down, Yume would once again space out while looking at the scenery outside- though right now, just the thought of the serenity that would become present soon was enough for Yume.

The eve of a pleasant moment...

**Notes for the Chapter:**

> yoru uses kansai ben but i have no idea how to reflect it on english so... gang


	6. Transduction

**Summary for the Chapter:**

> no chillin! fightin.

"Say, what does the cerebral cortex do?"

  
"It's responsible of functions such as awareness, thought, memory, language and attention. Is it not?"

  
Catching Yume and Sora walk to the library, Fubuki decided that it'd be a good idea to tail them with Nadare.

  
"..."

  
"Am I correct?" Yume questioned Nadare with a sincere smile, her enjoyment caused by Nadare's bravado evident on her expression.

  
"...You're correct! But that doesn't change that what you told me is extremely surface-level information!" Nadare pointed his finger at Yume with an angry expression as if he was being belittled by her. Fubuki was holding onto Nadare's free arm, joyfully watching the small conflict of his twin and Yume.

  
"You really do not have to test me. Is this some kind of affaire d'honneur to you?"

  
"YES."

  
Sora, walking next to Yume, was once again getting fed up with the antics of his younger brothers. With a furious manner, he scolded, "Won't you just shut up?! There's no one here trying to challenge you, damned hooligan!"

  
"This is not a matter of a challenge and not your business! Tell me, what are the main parts of central nervous system?" Nadare, quickly ignoring his elder brother, once again questioned Yume.

  
"Hmm, I don't know this one."

  
"Huh- really?"

  
"Really."

  
"Ah. As expected." Nadare maliciously smirked at Yume and Sora as if he was the winner of some kind of duel, though this didn't bother Yume at all, Sora was irritated to say the least.

  
"So, what are it's main parts?" Yume asked with a gentle smile, her happy expression never faltering despite having a demon on both of her shoulders (unfortunately, between Fubuki and Yume stood Nadare, leaving Yume between Sora and Nadare).

  
"Eh? The brain and the spinal cord. I'm disappointed you don't even know this." said Nadare with a condescending tone.

  
"Hmm. I'll make sure to remember it."

  
"Yume," Sora interrupted, now being out of temper, growled "you really don't have to play into his hands.", getting a glare from his brother.

"No, no," Yume chuckled lightly, "we're socializing right now. Are we not?" 

Yume's statement earned a doubtful look from Nadare and a shrug from Sora. Brightly chiming in, "Nadare and Yume-nee-san seem to get along~" cooed Fubuki. Looking at the glare his elder brother was giving him, with a slight worry in his smile, he continued, "Hey, hey, Nadare, let's leave Nii-san and Nee-san alone for now?"

"Definitely, great idea. I've been getting fed up with being beside Aniue-sama, anyway."

"That vain 'Aniue-sama' doesn't compensate for your disrespect, you embarrassment of a brother!" Sora snapped at his brother, only to be mildly scolded by Yume on his right.

"Sora, you shouldn't be so harsh on your brothers."

Sora only looked at Yume with an angry expression and then turned his head to the side while Nadare was still doubtful of the meanings behind Yume's actions. Deciding to worry about it later, dragging the slightly frightened Fubuki along him, he left his elder brother's side.

Looking at Nadare and Fubuki's disappearing figures as they were leaving the scene, after making sure that they were far enough to not hear the conversation of him and Yume, Sora calmed himself down and called out to Yume.

"Surely you knew the main parts of the central nervous system, isn't that right?"

"...Of course I did. Do I look like I don't know?"

"Why wouldn't you just say so?"

"Because Nadare wanted to hear me say 'I don't know'. It's good to be kind on youth, Sora."

"...They do not count as youth when they're only around a year younger than us. Isn't this your usual kindness?"

"No, I wouldn't accept someone older than me disrespecting me. It's the newer generations that'll surprass the older ones, after all."

After processing Yume's line in his head and deciding that he likes it, Sora cockily declared, "Yes, it might be true that newer generations will surprass the older ones," with a smirk, Sora turned to Yume, his words giving away the sibling rivalry between them, "but my brothers won't surprass me."

**Notes for the Chapter:**

> this doesn't have to be explicit, but despite being related by blood sora has different eye and hair colour than his siblings. yes, they're blood related, no plot twists here.


End file.
